Neck pain to the left is usually due to pathological factors, often associated with pillow fall, muscle strain, cervical spondylosis, frozen shoulder, etc., it is recommended to consult a doctor in time to identify the cause of the disease. 1. Falling pillow: falling pillow is usually due to poor sleeping posture, improper pillow and other bad postures, resulting in neck and shoulder muscle sprains, acute pain, limited movement symptoms, may show neck to the left pain. 2. Muscle strain: Muscle strain is a chronic, cumulative injury. If the cervical spine is in a state of long-term stress, and the neck muscles are continuously tense, it is easy to cause muscle strain, so that the local muscle pain, muscle strength decline, and then show the neck to the left pain. 3. Cervical spondylosis: Due to long-term strain on the cervical spine, degenerative disease occurs, the cervical disc herniation makes the nerve root or vertebral artery pressure, which will cause radiating pain. If the cervical disc protrudes to the left rear, it can stimulate the left side of the nerve root, and the pain occurs when the neck turns to the left. 4. Frozen shoulder: If there is frozen shoulder on the left side, the adhesion of muscles, ligaments, joint capsule and other structures near the shoulder joint will cause pain in the left shoulder and restriction of activities, which will cause pain when the neck is turned to the left. In addition to the above reasons, muscle fibrositis, trauma and other diseases can also cause the neck to turn to the left. If you have neck pain that is difficult to relieve on its own, it is recommended to seek medical advice and treatment under the guidance of a doctor.